Cisco IP Phones dropping calls out of the blue

[Hankejp]

Just wondering ifanyone has come across this problem. In one of our buildings we have multiple users who when talking on their 7940's are having their calls drop. There's no noise or anything when the calls drop the phone just goes dead. The user can dial a new number right away and the phone doesn't reset. It can be when talking to a number outside the business or inside, IP to IP, IP to Mitel, it doesn't matter. We had some engineers look at all of our routing logs and they say everything seems to be fine with them. The next step for us is to wait for a user to get a call dropped and to look in the logs as to why it was dropped.

Just wondering if anyone is or has experienced this problem.

 

[jneiberger]

Are all of these users connected to the same switch?

 

[Hankejp]

No their not. I forgot to mention, that we have changed the ports on the switch, replaced the phones, switches, network cables, everything. Nothing helped.

 

[jneiberger]

Have you opened up a TAC case? If so, do they have any ideas?

 

[Hankejp]

No I haven't opened anything up yet. I was going to see if anyone here knew anything, and I was going to wait for a user to call me so I can take a look at the log file, and let them know what the logfile says.

 

[jneiberger]

Hmm... this is a weird one. It doesn't sound like it's related to CallManager, unless CM is signalling the phones to drop the calls.

Does it only happen on the 7940s, or is that just the most typical phone in that building?

What version of CallManager are you running?

 

[Hankejp]

I believe that we only have 7940's in that building, but that shouldn't matter. We just upgraded our CM's form 3.3 to 4.1. Yeah it's very weird.

On a side note, my neighbor is in IT and the company he used to work for had the same problem. They had a TAC opened and Cisco couldn't figure out the problem. So they got rid of their Cisco Phones. That may have been a while ago though.

 

[pndscm]

I would do a bug search on the phone load that CCM is downloading to the phones. You should make sure you have the latest/greatest phone loads. I had a somewhat similar problem on a CCM 3.3.5 install and phone load was the problem. My phones would unregister on their own and not re-register without a power down.

 

[jneiberger]

That's a good point. What is the phone load on those phones?

 

[Hankejp]

I'll have to look tomorrow to see what the load is. How do I tell what the phone load is? I've recently just taken over this whole phone system.

 

[pndscm]

Go under Settings button and look under I believe it's the 5th option ?? I don't have a phone in front of me to look at. Sorry.

 

[jneiberger]

Any new info on this problem? I'd really like to find out if you've found a solution, or at least the cause of the problem.

 

[MG2005]

did this start right after you upgraded?

def check the default phone loads (system/device defaults) (or you can click on a troubled phone's ip address in the phone config screen and see what FW they are on)

sounds like the FW and CM release yoru running arent playing nice

P00307000200 (7.0(2) and
P00307020200 (7.2(2) are both pretty solid and fairly new FW loads, i use them both with CM 4.1.2

you can try debugging some live calls to and hope you capture some data on why a call terminated. Also i wonder if the serviceability or another built in troublshooting tool can help, I never used them yet tho

 

[Hankejp]

No News yet. This was happening before we upgraded. I am patiently waiting for one of my users to call saying that they just had a call drop. Problem is that most users are gone for the summer (School enviornment). They should be coming back soon, so hopefully I'll have some action then. I will keep everyone posted.

Would the phone loads be the same for everyone. For example; I have a 7960, would my phone load be the same as the 7940's? I just ask cause I'm being too lazy to walk over to the new building.

Thanks

 

[Hankejp]

On my 7960, the App Load ID is P00307010200. I don't know if thats the phone load or not.

 

[MG2005]

yes the app load is the Firmware-

check teh release notes for that load id, i bet theres some bugs

the loads are the same for everyone if that load is located under system/device defaults (the load you have in that field is the default for all devices of that model/type)

You can change individual phones to a different FW/Load on the phone config page. Thats great for troubleshooting or testing out a new FW laod before applying it to all devices.

 

[jneiberger]

I just looked and I don't see that problem listed in the Known Issues section of the 7.1(2) release notes.

 

[jneiberger]

I don't see anything like this in the Bug Toolkit for 7.1(2), either. I would think this would be a Severity 2 bug (or maybe even 1) but there is nothing worse than a Severity 3 listed in the Bug Toolkit.

 

[Hankejp]

I think I'll have to just wait until a user calls so Ican look in the logs. My neighbor old employment had what appeared to be the same thing happen and Cisco couldn't figure it out according to him. His company got rid of the Cisco system. I hope that's not the case here.

 

[MG2005]

funny that i neevr even heard much about FW 7.1-

I was running 7.0 and found out about 7.2 which fixed a few call quality issues i was having. But never even saw 7.1 come out in between

Cisco recommends 7.2(2) for ver 4.1.2. Just be careful if you use alot of shared line appearances theres a bug in there for that (4.1.2 ES29 fixes it tho).

7.0(2) is VERY solid otherwise, just a tiny few phones had an intermittent echo/call quality issue so i upgraded just those phones to 7.2(2) for now-

I'll do some more reseacrh for your issue. I liek torubleshooting quality isssues and dropped calls phenomenons